Each time inspectors raised serious concerns about safety and the ability of staff to maintain order and control.

After a 2007 visit, inspectors called on the National Offender Management Service to send in a team to help the new director to stabilise the prison.

It was later decided this would not be necessary and inspectors say there have been improvements in safety, but Rye Hill is still not yet an “effective training prison”.

The latset report states “staff remained stretched, and managers needed to be much more visible on the wings to support staff and address prisoners’ concerns” and “nearly half the prisoners reported having felt unsafe, although this was an improvement on the findings at the last inspection.”

The report also revealed the level of assaults and staff use of force had reduced, and the number of positive drug tests had also reduced.

Chief Inspector of Prisons Dame Anne Owers said: “Rye Hill has had a very troubled history since it opened.

“On three previous occasions we have reported fundamental failings in safety and identified a worryingly overstretched staff unable to ensure order and control.

“To the credit of G4S and senior managers, this inspection found a more stable and better managed prison, with evident improvements in safety.

"However, staff remained hard pressed and a great deal more work will be required in a range of areas if Rye Hill is to become an effective training prison.”

Phil Wheatley, director general of the National Offender Management Service, added: “Constructive relations with prisoners, aided by a reduction in the use of force by staff, reduce the likelihood of re-offending on release.

“However, as the report makes clear there remains further work to do in areas like training, safety and resettlement to ensure we meet our objectives of protecting the public and cutting re-offending.”